resolved: transaction - move DNS UDP socket creation to the scope

With access to the server when creating the socket, we can connect()
to the server and hence simplify message sending and receiving in
follow-up patches.

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index ce419f1a0414c7191b1d4d2673d3f7bccf3f130f..5129412604eb304752796451811620d6f8480e0e 100644 (file)
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -148,24 +148,20 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
                 if (DNS_PACKET_QDCOUNT(p) > 1)
                         return -EOPNOTSUPP;
 
-                srv = dns_scope_get_dns_server(s);
-                if (!srv)
-                        return -ESRCH;
-
-                family = srv->family;
-                addr = srv->address;
-                port = 53;
-
                 if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
                         return -EMSGSIZE;
 
                 if (p->size + UDP_PACKET_HEADER_SIZE > mtu)
                         return -EMSGSIZE;
 
-                fd = transaction_dns_fd(t);
+                fd = transaction_dns_fd(t, &srv);
                 if (fd < 0)
                         return fd;
 
+                family = srv->family;
+                addr = srv->address;
+                port = 53;
+
         } else if (s->protocol == DNS_PROTOCOL_LLMNR) {
 
                 if (DNS_PACKET_QDCOUNT(p) > 1)
@@ -200,7 +196,7 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
         return 1;
 }
 
-int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
+static int dns_scope_socket(DnsScope *s, int type, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
         DnsServer *srv = NULL;
         _cleanup_close_ int fd = -1;
         union sockaddr_union sa = {};
@@ -244,13 +240,15 @@ int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *add
                         return -EAFNOSUPPORT;
         }
 
-        fd = socket(sa.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
         if (fd < 0)
                 return -errno;
 
-        r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
-        if (r < 0)
-                return -errno;
+        if (type == SOCK_STREAM) {
+                r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+                if (r < 0)
+                        return -errno;
+        }
 
         if (s->link) {
                 uint32_t ifindex = htobe32(s->link->ifindex);
@@ -293,6 +291,14 @@ int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *add
         return ret;
 }
 
+int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server) {
+        return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, 53, server);
+}
+
+int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
+        return dns_scope_socket(s, SOCK_STREAM, family, address, port, server);
+}
+
 DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) {
         char **i;
 

diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h
index 21a160ea392950c4b444a18ec6233958bd505a2d..9d08bc325962f92a49d62aa47e1ecef5adfcb2aa 100644 (file)
--- a/src/resolve/resolved-dns-scope.h
+++ b/src/resolve/resolved-dns-scope.h
@@ -67,6 +67,7 @@ DnsScope* dns_scope_free(DnsScope *s);
 
 int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **server);
 int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server);
+int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server);
 
 DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain);
 int dns_scope_good_key(DnsScope *s, DnsResourceKey *key);

diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index 5540cd386e2e4b131ca681dbf33501ab37b8c722..5580e376c073f0961d3a80b1ba7f193fec43d319 100644 (file)
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -663,7 +663,8 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use
         return 0;
 }
 
-int transaction_dns_fd(DnsTransaction *t) {
+int transaction_dns_fd(DnsTransaction *t, DnsServer **_server) {
+        DnsServer *server;
         int r;
 
         assert(t);
@@ -673,14 +674,17 @@ int transaction_dns_fd(DnsTransaction *t) {
         if (t->dns_fd >= 0)
                 return t->dns_fd;
 
-        t->dns_fd = socket(t->scope->family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        t->dns_fd = dns_scope_udp_dns_socket(t->scope, &server);
         if (t->dns_fd < 0)
-                return -errno;
+                return t->dns_fd;
 
         r = sd_event_add_io(t->scope->manager->event, &t->dns_event_source, t->dns_fd, EPOLLIN, on_dns_packet, t);
         if (r < 0)
                 goto fail;
 
+        if (_server)
+                *_server = server;
+
         return t->dns_fd;
 
 fail:

diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h
index 1c8f82352afaeb79200348bb41e6a1edda9cd756..ab4db0612fd1e34eee46c68650d4196de6fe1d49 100644 (file)
--- a/src/resolve/resolved-dns-transaction.h
+++ b/src/resolve/resolved-dns-transaction.h
@@ -92,7 +92,7 @@ int dns_transaction_go(DnsTransaction *t);
 void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p);
 void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state);
 
-int transaction_dns_fd(DnsTransaction *t);
+int transaction_dns_fd(DnsTransaction *t, DnsServer **server);
 
 const char* dns_transaction_state_to_string(DnsTransactionState p) _const_;
 DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_;